Sex- and age-specific impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus in the development of disabling dementia in a Japanese population

BACKGROUND@#Sex- and age-specific impacts of cardiovascular risk factors on the development of dementia have not been well evaluated. We investigated these impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus on the risk of disabling dementia.@*METHODS@#The study participants were 25,029 (10,134 men and 14,895 women) Japanese aged 40-74 years without disabling dementia at baseline (2008-2013). They were assessed on smoking status (non-current or current), overweight/obesity (body mass index ≥25 kg/m2 and ≥30 kg/m2, respectively), hypertension (systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg or any antihypertensive medication use), and diabetes mellitus (a fasting serum glucose ≥126 mg/dL, non-fasting glucose ≥200 mg/dL, hemoglobin A1c ≥6.5% by the National Glycohemoglobin Standardization Program or glucose-lowering medication use) at baseline. Disabling dementia was identified as the level of care required ≥1 and cognitive disability grade ≥IIa according to the National Long-term Care Insurance Database. We used a Cox proportional regression model to estimate hazard ratios and 95% confidence intervals (95% CIs) of disabling dementia according to the cardiovascular risk factors and calculated the population attributable fractions (PAFs).@*RESULTS@#During a median follow-up of 9.1 years, 1,322 (606 men and 716 women) developed disabling dementia. Current smoking and hypertension were associated with a higher risk of disabling dementia in both sexes, whereas overweight or obesity was not associated with the risk in either sex. Diabetes mellitus was associated with a higher risk only in women (p for sex interaction = 0.04). The significant PAFs were 13% for smoking and 14% for hypertension in men and 3% for smoking, 12% for hypertension, and 5% for diabetes mellitus in women. The total PAFs of the significant risk factors were 28% in men and 20% in women. When stratified by age, hypertension in midlife (40-64 years) was associated with the increased risk in men, while diabetes mellitus in later-life (65-74 years) was so in women.@*CONCLUSIONS@#A substantial burden of disabling dementia was attributable to smoking, and hypertension in both sexes and diabetes mellitus in women, which may require the management of these cardiovascular risk factors to prevent dementia.

Safety, immunogenicity & effectiveness of the COVID-19 vaccine among healthcare workers in a tertiary care hospital

Background & objectives: The COVID-19 pandemic has caused significant global morbidity and mortality. As the vaccination was rolled out with prioritization on healthcare workers (HCWs), it was desirable to generate evidence on effectiveness of vaccine in prevailing real-life situation for policy planning. The objective of the study was to evaluate the safety, effectiveness and immunogenicity of COVID-19 vaccination among HCWs in a tertiary care hospital. Methods: This prospective observational study was undertaken on the safety, immunogenicity and effectiveness of the ChAdOx1 nCoV- 19 coronavirus vaccine (Recombinant) during the national vaccine roll out in January-March 2021, in a tertiary care hospital, New Delhi, India. Results: The vaccine was found to be safe, with local pain, fever and headache as the most common adverse events of milder nature which generally lasted for two days. The adverse events following vaccination were lower in the second dose as compared to the first dose. The vaccine was immunogenic, with seropositivity, which was 51 per cent before vaccination, increasing to 77 per cent after single dose and 98 per cent after two doses. Subgroup analysis indicated that those with the past history of COVID-19 attained seropositivity of 98 per cent even with single dose. The incidence of reverse transcription (RT)-PCR positive COVID-19 was significantly lower among vaccinated (11.7%) as compared to unvaccinated (22.2%). Seven cases of moderate COVID-19 needing hospitalization were seen in the unvaccinated and only one such in the vaccinated group. The difference was significant between the fully vaccinated (10.8%) and the partially vaccinated (12.7%). The hazard of COVID-19 infection was higher among male, age >50 yr and clinical role in the hospital. After adjustment for these factors, the hazard of COVID-19 infection among unvaccinated was 2.09 as compared to fully vaccinated. Vaccine effectiveness was 52.2 per cent in HCWs. Interpretation & conclusions: ChAdOx1 nCoV-19 coronavirus vaccine (Recombinant) was safe, immunogenic as well as showed effectiveness against the COVID-19 disease (CTRI/2021/01/030582).

Anemia as a risk factor for tuberculosis: a systematic review and meta-analysis

BACKGROUND@#Tuberculosis is a major public health problem caused by Mycobacterium tuberculosis, occurring predominantly in population with low socioeconomic status. It is the second most common cause of death from infectious diseases. Tuberculosis becomes a double burden among anemic patients. Anemia increases an individual's susceptibility to infectious diseases including tuberculosis by reducing the immunity level. Therefore, the purpose of this study was to determine whether anemia is a risk factor for tuberculosis.@*METHOD@#Relevant published articles were searched in electronic databases like PubMed, Google Scholar, EMBASE, and Cochrane Library using the following MeSH terms: risk factor, predictors, tuberculosis, TB, Anaemia, Anemia, hemoglobin, Hgb, and Hb. Articles written in the English, observational studies conducted on the incidence/prevalence of tuberculosis among anemic patients, or papers examined anemia as risk factors for tuberculosis were included. From those studies meeting eligibility criteria, the first author's name, publication year, study area, sample size and age of participants, study design, and effect measure of anemia for tuberculosis were extracted. The data were entered using Microsoft Excel and exported to Stata version 11 for analysis. The random-effects model was applied to estimate the pooled OR and HR, and 95% CI. The sources of heterogeneity were tested by Cochrane I-squared statistics. The publication bias was assessed using Egger's test statistics.@*RESULTS@#A total of 17 articles with a 215,294 study participants were included in the analysis. The odd of tuberculosis among anemic patients was 3.56 (95% CI 2.53-5.01) times higher than non-anemic patients. The cohort studies showed that the HR of tuberculosis was 2.01 (95% CI 1.70-2.37) times higher among anemic patients than non-anemic patients. The hazard of tuberculosis also increased with anemia severity (HR 1.37 (95% CI 0.92-2.05), 2.08 (95% CI 1.14-3.79), and 2.66 (95% CI 1.71-4.13) for mild, moderate, and severe anemia, respectively).@*CONCLUSION@#According to the current systematic review and meta-analysis, we can conclude that anemia was a risk factor for tuberculosis. Therefore, anemia screening, early diagnose, and treatment should be provoked in the community to reduce the burden of tuberculosis.

Association between Baseline SBP/DBP and All-Cause Mortality in Residents of Shanxi, China: A Population-based Cohort Study from 2002 to 2015 / 生物医学与环境科学（英文）

Objective@#To investigate the association between blood pressure and all-cause mortality in Shanxi, China.@*Methods@#The '2002 China Nutrition and Health Survey' baseline data in Shanxi province was used. A retrospective investigation was performed in 2015. The effects of SBP and DBP on the all-cause mortality were analyzed using the Cox regression model. The hazard ratio ( @*Results@#The follow-up rate was 76.52% over 13 years, while the cumulative mortality rate for all participants was 917.12/100,000 person-years. The mortality rose with an increasing SBP ( @*Conclusion@#Adults with SBP > 160 mmHg and DBP > 100 mmHg had a higher mortality risk. Sex and age difference was noted in both DBP and mortality risk.

Internal limiting membrane peel: Does it change the success rate of primary vitrectomy without belt buckle in rhegmatogenous retinal detachments?

Purpose: To compare the anatomic success of pars plana vitrectomy (PPV) after internal limiting membrane (ILM) peeling at macular area and macular plus peripapillary area versus no peeling in rhegmatogenous retinal detachments (RRD). Methods: A prospective observational study between July 2014 and March 2017 conducted on 289 eyes of 287 patients with RRD were randomly assigned to three treatment procedures, viz., PPV with no ILM peeling, PPV with macular peeling, and PPV with macular plus peripapillary peeling. Recurrent RD (ReRD) was treated as an event and accordingly the overall primary (PS) and final success (FS) rates were obtained. The risk of ReRD associated with peeling procedures after adjusting for risk factors were obtained using Cox-proportional hazard analysis. Results: The PS percentage for no peel, macular, and macular plus peripapillary procedures were 77.78% (70/90), 82.18% (83/101), and 94.89% (93/98; maximum), respectively, which was statistically significant with a P value of 0.003. The FS percentage for no peel, macular, and macular plus peripapillary were 93.33%, 95.04%, and 100%, respectively, which was significantly different with a P value of 0.048. With reference to no peeling, the adjusted hazard ratio for macular peeling was 0.841 [95% CI: 0.44–1.60] while 0.235 [95% CI: 0.088–0.626] for macular plus peripapillary peeling. Conclusion: The anatomic success rate of PPV with macular plus peripapillary ILM peeling was significantly higher as compared to no peel category. The hazard of ReRD in patients undergoing macular plus peripapillary peel was significantly reduced as compared to no peel procedure.

Studies on Alzheimer Disease - Metformin Connection - A Brief Review

Metformin is the widely prescribed first line oral antidiabetic drug used in diabetes mellatus, type 2 . The global sales turnover of metformin runs into millions of dollars. The Increased risk of metformin (Met) users for developing Alzheimer disease (AD)is reported first in a study conducted in 2011. Since then, the subject has attracted the attention of the researchers as well as the pharmaceutical industry, resulting in a number of studies, both clinical as well as experiments on animals. Confusing results poured in , ranging from confirmation of the risk of AD to protection against developing AD , making the scenario, all the more intriguing . Added to the confusion, is the diversity of various studies as well as the parameters interpreting their results. Of the many clinical trials, some are retrospective cohort studies(Tseng Chin-Hsiao 2019) , case controlstudies (Imfeld P, et al.) Randomised studies (Hsu CC, et al.),double blind , cross over pilot studies. (Aaron Koenig et al.)and some longitudinal studies (Ng TP, et al.) , besides studies doing meta analysis .Of these studies most of the trials estimate the risk of development of dementia withmetformin alone (Tseng Chin-Hsiao 2019) or in comparison with other OHAs (Hsu et al,Chenget al.) .The other studies studied the effect of metformin on the cognition. (Moore EM, et al.).These trials have different out come measures, (like Hazard ratio, (HR) Odds(OR) ratio, relative risk (RR) etc.)which don’t mean one and the same. So the multiplicity of the types of studies and different out-comes with different conclusions will be surely baffling to an average reader who tries to take cognisance of the involved issues. The article attempts to take stock of the overall developments in this regard. The author adopted a reader friendly approach which is discussed in the article, at the outset. Finally, it is reiterated that future prospective studies only can resolve the conflict of opinion on the nexus between metformin and Alzheimer’s disease

Application of restricted mean survival time in clinical follow-up study / 中华流行病学杂志

In clinical follow-up studies,hazard ratio (HR) is routinely used to quantify the differences between-groups,however,it is being estimated by the Cox procedure.HR,the ratio of two hazard functions has abstract meaning only and is in lack of the context to give an intuitive explanation of the survival of patients and the assumption of proportional hazards (PH) must be satisfied.Under this context,the restricted mean survival time (RMST) can be used as a relatively effective measure or index of statistics.This paper introduces the RMST-based statistical analysis methods,including estimation of RMST and its difference,hypothesis testing and regression analysis.The application of RMST in data analysis is also introduced.All the evidence demonstrates that RMST can be used as an effective analytical tool with straightforward interpretation.RMST is also more effective than HR in comparing differences between groups,when non-PH is observed.Therefore,RMST is suggested to be stated along with HR in the process of disease efficacy evaluation and prognosis analysis.Cooperation and complement of the two,a precise reflection on the characteristics of data can be expected.

What Should We Consider Carefully When Performing Survival Analysis? / 임상소아혈액종양

The survival data and the survival analysis are the data and analysis methods used to study the probability of survival. The survival data consist of a period from the juncture of a start event to the juncture of the end event (occurrence event). The period is called the survival period or survival time. In this way, the method of analysing the survival time of subjects and appropriately summarizing the degree of survival is called survival analysis. To understand and analyse survival analysis methods, researchers must be aware of some concepts. Concepts to be aware of in the survival analysis include events, censored data, survival period, survival function, survival curve and so on. This review focuses on the terms and concepts used in the survival analysis. It will also cover the types of survival data that should be collected and prepared when using actual survival analysis method and how to prepare them.

The relationship between hazard ratio and median survival time / 中华预防医学杂志

The hazard ratio and median survival time are the routine indicators in survival analysis. We briefly introduced the relationship between hazard ratio and median survival time and the role of proportional hazard assumption. We compared 110 pairs of hazard ratio and median survival time ratio in 58 articles and demonstrated the reasons for the difference by examples. The results showed that the hazard ratio estimated by the Cox regression model is unreasonable and not equivalent to median survival time ratio when the proportional hazard assumption is not met. Therefore, before performing the Cox regression model, the proportional hazard assumption should be tested first. If proportional hazard assumption is met, Cox regression model can be used; if proportional hazard assumption is not met, restricted mean survival times is suggested.

Application of restricted mean survival time in clinical follow-up study / 中华流行病学杂志

In clinical follow-up studies,hazard ratio (HR) is routinely used to quantify the differences between-groups,however,it is being estimated by the Cox procedure.HR,the ratio of two hazard functions has abstract meaning only and is in lack of the context to give an intuitive explanation of the survival of patients and the assumption of proportional hazards (PH) must be satisfied.Under this context,the restricted mean survival time (RMST) can be used as a relatively effective measure or index of statistics.This paper introduces the RMST-based statistical analysis methods,including estimation of RMST and its difference,hypothesis testing and regression analysis.The application of RMST in data analysis is also introduced.All the evidence demonstrates that RMST can be used as an effective analytical tool with straightforward interpretation.RMST is also more effective than HR in comparing differences between groups,when non-PH is observed.Therefore,RMST is suggested to be stated along with HR in the process of disease efficacy evaluation and prognosis analysis.Cooperation and complement of the two,a precise reflection on the characteristics of data can be expected.

Glycated Hemoglobin and Cancer Risk in Korean Adults: Results from Korean Genome and Epidemiology Study

The purpose of this study was to test whether elevated glycated hemoglobin A1c (HbA1c) levels are associated with cancer incidence in the Korean population. In cohorts of the Korea Genome and Epidemiology Study (KoGES) consortium, we tested whether plasma levels of HbA1c were associated with all-site cancer incidence in 7,822 participants without any known history of cancer or diabetes. Cancer developed in 117 participants during the follow-up period. Subjects were subdivided into 3 categories according observed levels of HbA1c (< 5.7%, low; ≥ 5.7% and < 6.5%, mid; and ≥ 6.5%, high). The adjusted hazard ratio for all-site cancer was 3.03 (95% confidence intervals, 1.54–5.96) for the high HbA1c group relative to the low HbA1c group after adjusting for covariates. Higher circulating HbA1c levels were associated with an increased risk of all-site cancer in Korean population.

Survival analysis: Part I — analysis of time-to-event / 대한마취과학회지

Length of time is a variable often encountered during data analysis. Survival analysis provides simple, intuitive results concerning time-to-event for events of interest, which are not confined to death. This review introduces methods of analyzing time-to-event. The Kaplan-Meier survival analysis, log-rank test, and Cox proportional hazards regression modeling method are described with examples of hypothetical data.

Disparities by Age, Sex, Tumor Stage, Diagnosis Path, and Area-level Socioeconomic Status in Survival Time for Major Cancers: Results from the Busan Cancer Registry

Our goal was to examine the effect of area-level deprivation on patient survival time for seven major cancers — stomach, colon, liver, lung, breast, cervix, and thyroid cancer. Data on 10,902 subjects who were diagnosed with major cancers from 2010 and 2011 in Busan were collected regarding the survival time along with several important prognostic factors and an area-level deprivation index was constructed from education, income, unemployment, and welfare assistance, to assess the comprehensive area-level socioeconomic status. A multilevel Cox proportional hazard model was used to investigate the effects of multiple risk factors such as gender, age, tumor stage, diagnosis path, and the area-level deprivation. After adjusting for risk factors the area-level deprivation index was found to be significant in associating with higher hazard rate for several cancers. Estimated hazard ratios (95% CI) were 1.08 (0.99–1.18), 1.23 (1.12–1.36), 1.36 (1.21–1.53) for the second, the third, and the fourth quartile of deprivation index groups, respectively, when compared to the least deprived group. When compared with the least deprived group, the more deprived group showed significant decrease in survival time for major cancers. This novel finding may contribute to the literature regarding the association of area-level socioeconomic status and highlight the importance of careful monitoring of socioeconomic characteristics for cancer prevention and care services.

Os fatores clássicos e a falha dos implantes dentários: qual o significado estatístico para a prática clínica? / On classic factors and dental implant failures: what is the statistical significance for the daily practice?

Objetivo: identificar quais dos fatores clássicos (material, desenho, superfície do implante, hospedeiro, técnica cirúrgica, protocolo de carga) possuem significado estatístico no prognóstico dos implantes. Material e métodos: uma busca eletrônica foi realizada no sistema PubMed/Medline até junho de 2015 com palavras-chave representativas dos estimadores, combinadas por operadores booleanos. Foram incluídos estudos clínicos contendo amostras com pelo menos 50 pacientes e 100 implantes, mínimo de um ano de acompanhamento, apresentando os estimadores obtidos através de modelo de Cox (Hazard ratio) ou regressão logística (Odds ratio, Risk ratio). O desfecho primário foi a falha do implante. Resultados: das 871 referências iniciais, foram selecionadas 20 após leitura integral, com mais de dez mil pacientes e mais de 30 mil implantes. Nos artigos com modelo de Cox, foram identificados o tabagismo (valores entre 1,04 e 3,9), o diâmetro (valores HR entre 1,72 e 6,35) e o comprimento (valores HR entre 0,8 e 2,7) do implante, as técnicas cirúrgicas específicas para melhorar o leito receptor (HR entre 2 e 5), os protocolos de carga (HR entre 0,1 e 9,7), o operador (HR=4,2; um estudo) e a maxila (HR=10; um estudo). Nos artigos com regressão logística, foram identificados os maiores valores de risco para implantes de largo diâmetro (OR=4,25; um estudo), implantes colocados na região posterior da maxila (OR=6,83; um estudo) e ausência de gengiva queratinizada (OR=4,7; um estudo). Conclusão: os fatores têm frequência variada, dependem da homogeneidade das amostras e nem sempre demonstram significado estatístico. Possíveis explicações podem ser atribuídas para as falhas. Mesmo assim, a documentação clínica detalhada continua fundamental para anteciparmos problemas em áreas estratégicas.

Objective: to identify which of the classic factors (implant material, design, surface; host, surgical technique, loading protocol) can have a statistical significance on dental implant prognosis. Material and methods: an electronic search at the PubMed/Medline was made until June 2015 with representative keywords combined by Boolean operators. Clinical studies with at least 50 patients and 100 implants, 1 year of follow-up, having statistical estimators such as Cox model (Hazard ratio) or logistic regression (Odds ratio, Risk ratio) analyses were included. The primary outcome was implant failure. Results: of the 871 retrieved records, 20 references were finally selected, summing up more than 10 thousand patients and 30 thousand dental implants. For articles using the Cox´s model, tobacco (HR values between 1.04 to 3.9), diameter (HR between 1.72 to 6.35), and implant length (HR between 0.8 to 2.7); specific surgical techniques to improve the recipient bed (HR between 2 and 5), loading protocols (HR from 0.1 to 9.7), the operator (HR=4.2, one study), and the maxillary arch (HR=10, 1 study) were identified. For articles containing logistic regression, the highest chance values were identified for large diameter implants (OR=4.25, one study), implants at the posterior maxillary region (OR=6.83, one study), and the lack of keratinized gingiva (OR=4.7, one study). Conclusion: these factors have a varied frequency, depend on sample´s homogeneity, and not always provide statistical meaning. Possible explanations can be attributed to failures. Even thus, a detailed clinical documentation remains mandatory to anticipate problems in strategic areas.

Measure of the Rate at which Mortality in Type 2 Diabetes Mellitus Occurs: Protocol for a Systematic Review.

Introduction: Type 2 diabetes is the third largest cause of mortality in the United Kingdom, with about 50% of patients’ having developed complications at time of diagnosis. We consider that the evidence which explores the actual hazard ratios of mortality has not been consistent. n this paper we discuss methodology and review the most recent accurate data on mortality in type 2 diabetes. Methods: A systematic review will be undertaken aimed at synthesis of evidence of relative risk of mortality in type 2 diabetes, using the Centre for Reviews and Dissemination guidelines. We will explore conflicting and unanswered questions in relation to mortality. The primary outcome is all-cause, overall-cause or total mortality expressed as hazard ratios. Sub-groups will also be explored; age, gender, socio-economic factors and causes of death. We will review abstracts published after 1990 in the English language. Our data source will include electronic databases; the Cochrane library, the Centre for Reviews and Dissemination, Medline/PubMed, and other grey literature. The study populations are type 2 diabetes patients whose mortality outcome, expressed as hazard ratio, has been evaluated. Data extraction will be undertaken by one reviewer and triangulated by the second and third reviewer. The quality of the included studies will be evaluated in accordance with the inclusion/exclusion criteria; methodological quality that meets the critical appraisal framework and the relevance to the research questions. Evidence from data will be synthesised through a descriptive epidemiological review from included studies; meta-analysis will be used if appropriate. Result & Conclusion: We expect to pool homogenous studies of large population cohorts which explore the hazard ratio of mortality, and to summarise the evidence of the actual mortality risk in type 2 diabetes, with limited bias. This will help direct future research in areas of unanswered questions and may influence healthcare policy decisions.

High-sensitivity C-reactive Protein Can Predict Major Adverse Cardiovascular Events in Korean Patients with Type 2 Diabetes

Inflammation is thought to play a role in the pathogenesis of major adverse cardiovascular events (MACE). It has been suggested that the measurement of markers of inflammation may aid in predicting the risk of such events. Here, the relationship between high-sensitivity C-reactive protein (hs-CRP) levels and MACE in Korean patients with type 2 diabetes is assessed. A retrospective cohort study was conducted as a follow-up among 1,558 patients with type 2 diabetes and without cardiovascular diseases over a mean period of 55.5 months. A Cox proportional-hazards model was used to determine whether increased hs-CRP levels are useful as a predictor for future MACE. The hazard ratio of MACE was 1.77 (95% CI; 1.16-2.71) in subjects who had the highest hs-CRP levels (> 0.21 mg/dL) compared to subjects who had the lowest hs-CRP levels (< 0.08 mg/dL), after adjusting for age, regular physical activity, current smoking, and duration of diabetes. The present results indicate that high hs-CRP levels can act as a predictor for the MACE occurrence in Korean patients with type 2 diabetes.

Influence of Life-related Factors and Participation in Health Examination on Mortality in a 4.5-year Follow-up of a Rural Cohort

To identify life−related factors causing increased mortality, 2, 769 rural residents aged 29−77 were investigated through a self−administered questionnaire in 1990. Death certificates and migration information were inspected during the 4.5−year follow−up period. Age, obesity, life attitude, job, marital status, drinking and smoking habits, previous or current illness, and frequency of participation in health examinations were checked during the baseline survey. The person−year mortality rate was higher among irregular participants in health examinations than among regular participants both among males and females. From Cox’s multiple regression analysis, factors with a significantly high hazard ratio (HR) for mortality were irregular participation (HR=2.05), increase of age (HR=1.54, for 10 years), previous or current illness (HR=2.44), unemployment (HR=1.95), and living without a spouse (HR=2.61) for males; and for females they were having previous or current illness (HR=15.21) and living without a spouse (HR=2.94). Thus, irregular participation in health examinations, unemployment and aging showed a relationship with a higher mortality only in males. A previous or current illness and living without a spouse were related in both sexes.

Long-term Prognostic Value of Dipyridamole Stress Myocardial SPECT / 대한핵의학회잡지

PURPOSE: Dipyridamole stress myocardial perfusion SPECT could predict prognosis, however, long-term follow-up showed change of hazard ratio in patients with suspected coronary artery disease. We investigated how long normal SPECT could predict the benign prognosis on the long-term follow-up. MATERIALS AND METHODS: We followed up 1169 patients and divided these patients into groups in whom coronary angiography were performed and were not. Total cardiac event rate and hard event rate were predicted using clinical, angiographic and SPECT findings. Predictive values of normal and abnormal SPECT were examined using survival analysis with Mantel-Haenszel method, multivariate Cox proportional hazard model analysis and newly developed statistical method to test time-invariance of hazard rate and changing point of this rate. RESULTS: Reversible perfusion decrease on myocardial perfusion SPECT predicted higher total cardiac event rate independently and further to angiographic findings. However, myocardial SPECT showed independent but not incremental prognostic values for hard event rate. Hazard ratio of normal perfusion SPECT was changed significantly (p<0.001) and the changing point of hazard rate was 4.4 years of follow up. However, the ratio of abnormal SPECT was not. CONCLUSION: Dipyridamole stress myocardial perfusion SPECT provided independent prognostic information in patients with known and suspected coronary artery disease. Normal perfusion SPECT predicted least event rate for 4.4 years.